Add Typed Display Settings Administration

Implements admin-only Display settings with generation-checked
Apply, Save, Load, Defaults, and Reset operations across the web UI,
CLI, SSH dispatcher, and local UI owner. Adds bounded HTTP handling,
session-isolated operation results, browser lifecycle support, and
comprehensive host tests and documentation.

docs/agent/code-map.md

@@ -59,6 +59,8 @@ This is a semantic map, not a complete file inventory. Start here, then read the
 
 ## Web and WebSocket serial
 
+- **8D.14 Display (2026-09-09):** `web_display_settings.{c,h}` owns optional admin-only GET `/api/settings/display`, GET/POST `/api/settings/display-operation`; `web_ui.c` supplies Serial-style dim/off settings and bounded completion checks. `local_status_ui` owns generation-safe config/storage reservation shared with CLI; buttons do not edit timeouts. No I2C changes. 256-byte/four-receive request,128-byte snapshot,96-byte result, one slot/no timer;30 handlers/six sockets, unchanged tasks/stacks/queue/schema. Tests: cookie `--display` (7+shared), UI111, lifecycle23, dispatcher and broad regressions. Actual baseline100,100/1,748,513 B → final100,196 RAM/1,765,233 flash at160MHz. Target pending; exact API, reset ordering, deadlines, resource/validation limits: `docs/phase8d14_implementation.md`.
+
 - **Current 8D.12/8D.13 — user functional sign-off 2026-09-08, including Settings presentation:** `web_network_settings.{c,h}` owns optional admin-only GET `/api/settings/network` and GET/POST `/api/settings/network-operation`; `web_ui.c` supplies Network, UTF-8/hex SSID editing and explicit transient-secret/connection controls. `wifi_manager` owns generation-checked secret-free snapshots/patch/save/stored-only load and radio transitions; `mdns_service` owns independent conditional hostname persistence, with manager reannouncement. Existing dispatcher receives IDs only. 768-byte request/2,048-byte snapshot/128-byte result, one slot/one-second timer with 30-second queued expiry plus scheduling latency; no hard cancellation. 27 handlers/six sockets, no task/stack/queue/schema growth. Parent integrated tests/build PASS; latest styling UI100 + renderer/CSP/Chromium checks, 99,548 B RAM / 1,744,325 B flash. User full-mix evidence accepted; loaded internal/DMA minima2,276/156 B remain resource follow-ups, not reserve approval. Full contract/exclusions/checklist: `docs/phase8d12_13_implementation.md`. Both phases user-authorized together; no 8D.14/M3 claim. Older next-phase statements below are historical.
 
 - **8D.11:** `web_account_settings.{c,h}` extends Accounts with fingerprint-only POST `/api/settings/accounts/keys` and key-add/key-delete/key-clear on the existing operation endpoint/dispatcher. `user_database.{c,h}` owns zero-wait target-checked snapshots and canonical conditional key mutations. `web_ui.c` handles confirmations, sparse stable indices and self-revocation uncertainty. 24 handlers, six sockets; no new task/stack/queue depth. Host-tested/build-verified, target pending. Contracts/tests/checklist: `docs/phase8d11_implementation.md`.
@@ -160,12 +162,12 @@ This is a semantic map, not a complete file inventory. Start here, then read the
 **Responsibility:** own OLED I2C/framebuffer operations and present status plus constrained button actions.
 
 - Files: `src/local_display.{h,c}`, `src/local_status_ui.{h,c}`, `src/local_boot_animation.{h,c}`, `src/local_ui_config.{h,c}`, `src/local_ui_console.{h,c}`
-- Interfaces: display init/frame/draw/commit/snapshot; UI start/activity/config; versioned NVS settings
+- Interfaces: display init/frame/draw/commit/snapshot; UI start/activity/config; generation-checked settings projection/update and explicit persistence reservation; versioned NVS settings
 - Called by: startup, local UI task, diagnostics, display console
 - Dependencies: copied snapshots/public APIs from serial, broker, USB, Wi-Fi, web, SSH
 - Ownership: `local_display` solely owns I2C0 and framebuffer mutex; a frame belongs to its initiating task.
 - Lifecycle: the low-priority task is firmware-lifetime only if button GPIO initialization succeeds; it still runs with an absent panel so a press can reprobe after successful I2C bus setup. Failed bus creation is not recoverable by that reprobe, and `display` configuration commands depend on the UI task.
-- Constraint: collect service snapshots before I2C; local UI never joins broker or handles secrets.
+- Constraint: collect service snapshots before I2C; local UI never joins broker or handles secrets. All configuration writers honor the UI owner's zero-wait reservation; NVS runs outside timing critical sections. Reset commits defaults before RAM publication, including CLI; buttons/diagnostic holds update activity, not configuration generation.
 
 ## Hardware and diagnostics